An operating method of the type mentioned at the outset and a corresponding compressor are known from German Patent Application No. DE 10 2005 010 792. In that document, a pressure release valve configured as a pop-off valve is used in order to rapidly reduce the boost pressure produced by the compressor, by diverting the compressed air to a low-pressure side at the input to the compressor. A cyclic flow is generated thereby, among other things, through a bypass that includes the pop-off valve, which connects the high-pressure side of the compressor to its low-pressure side.
The usual method described using the pop-off valve makes possible a rapid reduction in the boost pressure. However, the problem with pressure equalization across the pop-off valve is that, in the case of a rapid load change of the internal combustion engine, for instance, from full load, at which a throttling device of the internal combustion engine is open all the way, to overrun, at which the throttling device is substantially closed, and subsequently renewed full load operation, the boost pressure on the output side of the compressor, that is, upstream of the throttling device, has to be generated anew. This brings about a delayed response of the internal combustion engine with respect to torque that is output as referred to the torque command of the driver.
Therefore, other usual design approaches provide that, alternatively or in addition to the pop-off valve in the bypass, one should position a second throttling device upstream of the compressor. At least in some operating states, these measures could prevent the undesired transfer of the compressor into a pumping state or even the complete dropping off of the boost pressure at rapid load change, but they require a comparatively large constructive expenditure in the form of an additional actuating mechanism and a correspondingly complex controller.